Rhubarb Bourbon Brown Butter Tart with Almond Crust

I’ve been eyeing Deb’s Cherry Brown Butter Bars (adapted from Bon Appetit’s Raspberry Brown Butter Tart) for what seems like forever. It’s actually only been since June 29, 2009. But four years without tasting buttery crust against fruit-studded brown butter custard might as well be eternity.

Yesterday, with a refrigerator full of rhubarb, I decided that enough was enough. I added sugared slices of my favorite “fruit,” a vanilla bean, and a splash of bourbon to the heaven-sent filling, and threw the whole thing in an almond press-in crust. It’s my new favorite dessert.

Whoever coined the term “easy as pie” obviously never made one from scratch. Pie dough is finicky, and challenging to get just right. (You should still make pie, though.) This tart dough, on the other hand, is stupid simple. Everything gets whizzed in the food processor until it begins to clump together, and the crumbs get dumped into the awaiting tart pan. It takes a bit of patience to press the edges and bottom into a smooth, even layer, but after a brief stint in the freezer, the crust holds itself up in the heat of the oven without needing the help of pesky pie weights. It ends up tasting like a buttery shortbread cookie kissed with salt and toasted almonds.

The filling is just as much of a breeze. The magic happens when you cook the butter with a vanilla bean until the milk solids caramelize and smell like baking cookies. This glorious golden substance gets whizzed, in the unwashed food processor bowl, into a custard of eggs, sugar and flour, then doused with a shot of bourbon. The custard is poured over the awaiting rhubarb-filled crust, and baked until puffed and golden.

The rhubarb turns meltingly tender as the tart bakes, and it retains its puckery tartness in the final dessert, which is, to my taste, perfectly sweetened. The bourbon adds a bit of subtle complexity to the custard; I can definitely sense its presence, but it melts into the background of nutty butter and floral vanilla. The crust is so tender, it crumbles under the merest pressure of a fork, though it holds together sturdily enough to transport slices from pan to plate. It is buttery and crisp against the creamy filling – ultra satisfying.

You could top this with a plume of softly whipped cream, flavored with vanilla and a splash of bourbon if you like, but the tart is more than adequate on its own. It’s an easy dessert to whip up for company who will think you spent an eternity making it. Little will they know.

Rhu-mania:

Rhubarb, Bourbon, and Brown Butter Custard Tart with Almond Crust

I do love the bourbon here, but the tart will still rock if you wish to omit it entirely or substitute brandy or another type of whiskey in its place. Be sure to trim away any rhubarb leaves as they are toxic. If you don’t have a food processor, you can easily make this by hand by chopping the almonds very finely, rubbing the buttery dough with your fingertips, and using a whisk and bowl to make the filling. I baked this in my favorite 8-inch tart pan which just barely held all of the filling; a 9-inch pan will work perfectly, too. This tart holds its own, but feel free to serve it with lightly sweetened whipped cream flavored with a splash of vanilla and bourbon.

In the bowl of a food processor, process the almonds, powdered sugar, salt and flour until the almonds are finely ground. Add the butter, and pulse until the mixture just begins to clump together. Dump the crumbs into an 8 or 9-inch tart pan with a removable bottom. Don’t bother washing the food processor bowl. Press the dough into the sides of the pan first, then the bottom, taking time to make square corners, a neat top, and an even thickness. (If the dough becomes soft or sticky, put the whole pan in the refrigerator for 5-10 minutes to firm it up again.) Prick the bottom of the crust all over with a fork. Freeze the crust until firm, 15 minutes, or wrap for longer storage.

Place the tart pan on a rimmed baking sheet for easy maneuvering, and bake the unlined crust until it is pale golden, 15-20 minutes, rotating after 10 minutes for even browning.

Meanwhile, make the filling:
Toss the sliced rhubarb with 2 tablespoons of the sugar in a medium bowl and set aside to macerate while you finish baking the crust and making the custard.

Place the butter and vanilla pod and scrapings in a medium, heavy-bottomed saucepan and cook over medium heat, swirling occasionally. After about 5-10 minutes, the butter will foam up, turn golden and smell nutty, with brown flecks mingling with black vanilla bean seeds. At this point, remove the pan from the heat. Remove the vanilla bean (you can rinse and dry it and stick it in a jar of sugar, or use it to make vanilla extract). Pour the butter into a heatproof measuring cup to stop the cooking, and let cool 5 minutes.

In the bowl of the food processor, pulse together the remaining 1/2 cup of sugar, the flour and salt to combine. Add the eggs, and process until combined. With the motor running, pour in the brown butter, including the brown flecks and vanilla seeds, then the bourbon.

Assemble, bake, and eat the tart:
Scrape the rhubarb and any juices into the hot, par-baked tart shell in an even layer. Carefully pour the custard over the rhubarb, filling the shell to the brim.

Bake the tart until the filling is puffed and browned, 30-45 minutes, rotating the tart halfway through for even baking. Remove the pan from the oven and let the tart cool until warm. Set the tart on an inverted bowl or ramekin, and ease off the ring. Sprinkle the tart with powdered sugar, cut it into wedges, and serve warm or at room temperature.

The tart keeps well in the refrigerator for several days; re-warm slices in an oven or toaster oven for best results.

Man, the way you describe every flavor aspect of this tart makes me want to make and eat an entire one right now! I've made a lot of rhubarb pies before, but I've never had a rhubarb + custard combo, and it sounds to die for.

Love the easy tart crust too. I kind of freak out about having to deal with pie dough in the summer, because the humidity makes it almost impossible to work with. Stupid simple sounds good to me! (:

Thanks, Carey – I think you'd like this one! Trying to wrastle (wrestle + rangle?) pie dough on a hot summer day is no fun. My first attempt at croissants took place in 100º heat; it was traumatic enough that I waited several years before I worked up the courage to try again!

Hi there! Just wanted to say that a friend of mine made this recipe last night and it was FANTASTIC! The only issue is that in the crust ingredients, it calls for 'cold' butter, but without any liquid to bind the crust, it doesn't keep together. Perhaps you meant 'melted'? The recipe on Epicurious calls for melted butter, as does the Smitten Kitchen one, and from your photos, it looks as though you melted the butter as well. Typo? Hope this helps, and as I said, it was simply divine!

Hi, Alanna! I'm so glad you guys liked the tart! I actually do use cold butter in the dough; I process it until it begins to clump together, like a shortbread. I've made it many times, and never had an issue with it not coming together. Processing it longer should do the trick. I did try a crust with melted butter once, and it was a spectacular failure that I never wished to repeat again! (I ramble on about it here: http://www.bojongourmet.com/2011/08/cherry-frangipane-tart.html) Cheers.

Confession: I've never tried rhubarb. It's a bit like admitting you've never watched E.T. or The Big Lebowski, but we've somehow always missed each other. I believe, however, that this dessert might possibly be the best introduction I could possibly hope for.

Oh, that's such a shame. I lived in Bologna for a year and it's true – I didn't see any rhubarb. If you happen to have any space for a garden, it seems to be fairly easy to grow, even just in a big pot. Hope you get your hands on some soon! Thanks for the note. :)

Being Alanna's gluten intolerant sister, I am incredibly lucky and consistently spoiled! If I am honest, I have to say I am not all that interested in cooking or baking, but eating is a favorite pastime. I see my sister often, about once a week, and my daughter and I are often the recipients of her latest baked goods. Last night was no exception. After seeing my daughter's senior recital, we all went out for Mexican food. After dinner, with her beautiful smile, Alanna handed us something wrapped in tin foil. This morning with my daily cup of earl grey tea I tasted the delectable tart shown above. As always, I was amazed by the flavors and the perfection of the crust, the perfect balance of sweet and tart, and the buttery yummmm that went so well with my hot tea. Every time I taste one of Alanna's magical baked goods I ask her if she will make it for my birthday. This is another one!

Hi! I'm so sorry for the confusion – the tart I gave my sister was actually a slightly different tart and one that I'm about to share. The post will up in a few days, so check back! (Her comment was so sweet, I didn't want to burst her bubble.)

I do think this recipe would convert pretty easily to gluten-free, however, by using sweet rice flour or a GF all-purpose blend in place of the wheat flour called for here (I would add an extra 2T flour to the crust). I don't have much experience baking with almond flour, but it's possible you could substitute that for all of the flour, too. Please let me know if you give it a go!

I wanted something other than Apple and rhubarb crumble for dessert, I found this recipe whilst googling around. Made it on Sunday night, ate it warm, ok,, ate it hot! It was amazing! My son and his girlfriend both brought slices for lunch on Monday, I got text messages from each of them telling me how incredibly delicious it was! So pleased!!! We finished it off in the evening. Thank you so much, this recipe's a winner!

Just made this tart almost exactly as written (omitted the bourbon and used a shade less butter in the filling…and used buckwheat flour in the filling, actually, because that's what I had on hand) and it was STUNNING. As is pretty much any recipe I make from your site, so I shouldn't have been surprised. But people were going nuts over the crust (heh) and it was just such a success, came home with four tiny pieces left in the pan. Thanks for the brilliant recipe, Alanna!!

Hey Erin, If I were you, I would look at some other recipes that use just almond flour and see how they work. Ps. I have a great GF tart crust in my upcoming book that uses almond and some other flours. ;)